Power Supplies

[Newbie2]

Re: Power Supplies

never mind about my last comment, I see this forum allows attachments-

Anyway, here are just a few failed units, I am sorry for the poor quality of the images.

psu001.jpg is the 200watt Achme from my shuttle XPC

psu002.jpg is a 300watt Antec

psu003.jpg is a 300watt codegen

psu004.jpg is another 300watt Antec

and

psu005.jpg is a 430 watt Antec Truepower

The Antec 300W power supplies look cheap on the insides to me. My old Enermax 300W (had PCE-TUR caps) had bigger heatsinks and more caps, plus bigger transformers.

[Oklahoma Wolf]

Re: Power Supplies

Does Enlight make their own p/s, or does someone else?

My memory might be a bit sketchy, but I believe Enhance makes them. I still tend to recommend Fortron to those needing a good PSU on the cheap, but if I start seeing Fuhjyyus go in them I may have to change my mind about that. I can tell you though my all Teapo 530W is doing ok after a year and a half - no cap issues. It had some cooling issues, but that's another story.

CWT/Antec designs always strike me as being quite good apart from the cap selection - methinks recapping one of them should get it to last a few years. Other than that, you'd probably have to buy something like a Zippy to get good caps out of the box; and their PSU's aren't the cheapest.

[Cprossu]

Re: Power Supplies

The Antec 300W power supplies look cheap on the insides to me. My old Enermax 300W (had PCE-TUR caps) had bigger heatsinks and more caps, plus bigger transformers.

What is strange is that the older Antec 300watt psu's seem to have larger sinks, transformers, and most importantly more decent caps than the newer ones. I used to have an Enermax 300watt, and it was because of that supply I switched to antec in the first place. (The 300watt enermax kept on shutting the system down and supplying bad power (EI wavering in voltages by ~1volt at times on the 5v rail) to components, whereas I bought a 300watt Antec and all the problems went away <although it's been some time since then>)

[willawake]

Re: Power Supplies

some different layouts than usual

Chieftec CFT-500 500w
http://www.chieftec.com/products/psu/atx_psu.htm

images taken from German site Cooling Station - review below
http://translate.google.com/translat...&hl=en&ie=UTF8







and Dark Power 470

review and images from Hardware Labs again German
http://translate.google.com/translat...&hl=en&ie=UTF8

[Oklahoma Wolf]

Re: Power Supplies

That first one is AcBel Polytech in origin... had to go into the review to find a pic of the label to be sure (traced the UL file number on it), but most of them look kinda like that with the two somewhat small main filter caps.

The second one is a Topower... easy to spot most of the time thanks to that "TOP" nomenclature on the transformers. Never saw a Topower arranged like that before though with the single large cap in the middle. Looks almost like a Seasonic design.

Not sure if you all are familiar with this website, but there are some fairly interesting innards pics here: http://terasan.info/dengen/index.html

[willawake]

Re: Power Supplies

many thanks indeed, what is your opinion about the greatly undersized main filter caps on the first unit. it would be expected to have 200v and at least 1000uf i guess for 500w. yet they are using 450v 150uf. they appear to be chemicon ripoffs?

we have availability of this unit here. costs euro 105. Acbel apparently offer 10 year warranty. via Chieftec here you get 1 year

thanks for the link. that site is excellent.

Tom's Hardware does have a labs where they tested psus for 6 weeks under full load. pity they did not pop the hoods.
http://www.tomshardware.com/2005/07/11/stress_test/

[Oklahoma Wolf]

Re: Power Supplies

Can't say for sure what's up with those little filter caps... they're a mystery to me. The only time I've even seen caps like that have been in AcBel units. AcBel is supposed to be decent quality though - the design must work for them. The ones in my Fortron 530W are huge in comparison... 1200uf@250v (don't remember the brand).

There are a couple other good sites I go to for good reviews: www.silentpcreview.com and www.xbitlabs.com.

I was going through Terasan after I posted the link and spotted an older Fortron using Fuhjyyu caps, so I guess they must have always used them for the little caps and then Teapo for the big ones. I should open up the 530W again - I know the huge secondary 6800uf caps are all Teapo, but now I'm starting to wonder what else is in there

[Oklahoma Wolf]

Re: Power Supplies

Can't edit so I'll post again... found a few AcBel units at Terasan to look over:
http://terasan.info/dengen/no075/index.html
http://terasan.info/dengen/no071/index.html

Is that a genuine Rubycon I see in the second to last pic in that last link?

[PeteS in CA]

Re: Power Supplies

Re the 150uF, 450V caps, does that P/S have active PFC? The 450V rating of the caps and the length of the primary-side heatsink suggests that possibility. If so, the two caps (if I saw correctly) would be in series, not parallel. Also the bus voltage will be regulated, typically 325V-350V, instead of unregulated, 250V-270V. The energy stored in a cap is .5(C)(V^2). Thus, the regulation and the higher bus voltage permit what might seem like wimpy capacitors. The two caps in parallel reduces the net ESR, and, since PFC is a high-stress application, those should be 105C parts. If the caps aren't from one of the three 'cons or Panasonic, I'd keep an eye on them. As harmonic currents regulations tighten and power levels rise, active PFC will become increasingly common.

Edit: I just noticed in the third pic that they are UCC, which is a good sign. I also noticed that the core of that large magnetic component, which is one of two large magnetic components, looks like ferrite. The core material and there being two large magnetic components are almost certain clues indicating active PFC.

[willawake]

Re: Power Supplies

pete what is the difference between active and passive pfc. does active not require the big transformer commonly attached to the lid. i can see no connector for that in the photos.

high power site has some info about PFC http://www.highpowersupply.com/product-pfc.htm
which is required for all EU PSU. well the L&C certainly dont have that.

[willawake]

Re: Power Supplies

by the way that chieftec has only a 12" fan and no exhaust fan.

expect more dumb questions. i am very interested but missing the background.

[stretch0069]

Re: Power Supplies

Antec cheap???? I bought a TruPower 430 about 3 years ago. I haven't fired it up in a couple months. Might have to check it out when I get home. When I bought it, everyone was recommending them. Hmmm...my how times change.

Oh well....further investigation to come......

[Oklahoma Wolf]

Re: Power Supplies

Re the 150uF, 450V caps, does that P/S have active PFC? The 450V rating of the caps and the length of the primary-side heatsink suggests that possibility. If so, the two caps (if I saw correctly) would be in series, not parallel.

I think most AcBel units I've seen like this do have active PFC, and them being in series makes a lot of sense to me.

Passive PFC circuits in PC PSU's usually employ just a big inductor IIRC - easy to spot.

[PeteS in CA]

Re: Power Supplies

pete what is the difference between active and passive pfc. does active not require the big transformer commonly attached to the lid.

Like OKW said, passive PFC uses relatively large, heavy, 50Hz/60Hz inductor. The inductor core will be made of steel laminations, hence the weight. The AC I/P current won't be pretty, but complies with harmonic current regs. Passive PFC is relatively inexpensive and easy to implement.

Active PFC is a separate, non isolated, inverter in which the O/P voltage is regulated and the shape of the I/P current is controlled so that it is fairly sinusoidal. I've seen some PFC designs where the I/P current is a near-perfect sine wave. It's higher cost, more complex, and the greater precision often isn't necessary. I think that, longterm, the trend is toward active PFC, but the regulators and the OEMs will be brawling over it for quite a while.

[willawake]

Re: Power Supplies

thanks for the explanation.
passive PFC though complicates the layman's PSU choice of the best psu based on weight. any with passive PFC will therefore be quite heavy no matter how crappy.

so in your opinion the chieftec is looking to be a good choice? the bigger 550w has a rather bad review in the Tom's hardware labs though.
http://www.tomshardware.com/2005/07/...est/page8.html

there is also Sharkoon, Silverstone, Enermax, Akasa, Seasonic availability here. i will try to find some interior pics.

[Oklahoma Wolf]

Re: Power Supplies

Silverstone and Akasa share Enhance as an OEM, however Silverstone also has a few Etasis made models (a fanless unit and the new 560W, 750W, and upcoming 850W units). I forget who Sharkoon is using. Always thought there was a link between Enermax and Superflower/TTGI, but could never confirm it.

Some Enhance innards with a Teapo main filter cap: http://terasan.info/dengen/no029/index.html

Etasis: http://terasan.info/dengen/no006/index.html

[willawake]

Re: Power Supplies

may i ask your profession. you recognise the oem of a lot of brands. thanks for joining us your input is greatly valued,

what is your preferred psu brand anyway.

[Oklahoma Wolf]

Re: Power Supplies

Right now I'm mostly a part time church secretary and novel writer. I've been in electronics repair however since I was 14 - ran my own business for a while. Never was really successful at it though... too many people around here would rather throw stuff away than get it fixed

I track down the OEM's of these things mostly by searching the UL database at www.ul.com using the file number from a PSU label, but sometimes that number isn't there so I have to go by other identifying marks on the PCB or other components. Usually I can figure them out but sometimes there's nothing to go on.

My own favorite is Zippy, but I don't own one. There's pics of a few of them at the Terasan site. I get by with Fortron-Source these days.

Here's a review of one of the Silverstone/Etasis units I mentioned: http://www.overclockersonline.com/in...num=337&pnum=0

Looks to be better quality than the 330W unit I linked above. Three main filter caps on this one - never saw that before on a PC PSU. Since this is an active PFC unit, they too may be connected series - now I want one so I can dissect it

Maybe PeteS can shed some light on the issue - he seems better at the engineering side of it than I am

[willawake]

Re: Power Supplies

i hope you have success with your novels.

the throw away society is everywhere unfortunately. zippy looked good under the scope of terasan. actually so did antec heh. we have no availability for zippy here though although we have seasonic.

i will pick up a silverstone some time to check that out.

[Oklahoma Wolf]

Re: Power Supplies

i hope you have success with your novels.

Thanks, after the week I had I needed that

Zippy is hard to find here too, but this new Silverstone is proving impossible. Nobody in Canada carries them that I know of. Too bad... I want one now